What board would I use for most fun in that range? I weigh 95-100 kgs. One has to be able to pull rig up on it. Today I use a 199l fanatic viper L for those sails but I'm thinking maybe there is something more daring that still works?
A 145 easily float's you, but you're asking for something for eleven meter sails, so it's either a SLW or a Formula board for the earliest planing in the lightest winds up to 22 mph. SLW's come around 152 liters, while Formula boards usually start at 162+ liters.
Formula boards have become short and straps are even more outboard than the above boards (8-12 range ??)
the above boards are more 8-11/12 and not 7-11
7 m² sails tend to be used in better winds and thus rougher water - not ideal for wide boards
I have used 7 meter sails on 80 cm wide boards, but that is about the limit
and 10 meter sails are about the limit for those boards as well !!
typically ideal sail range for a board is no more than 2 square meters and NOT four
like 6-8, 7-9, 8-10, etc ...
My 75 wide 115 litre 2011 Tabou Manta with my 7m sail is my fastest combo in 12-20 knots.
With the new model 42 Lockwood carbon fin it smokes in the gusts and thru the lulls / upwind is amazing.
When I used my 44 Sonntag - was starting to take off a bit in the 18-20 gusts 
Some of the older Carbon Art boards around 75 wide are awesome too.
recommended 6-10
ideal 6.5-9.5
for me that means ~7-9
OP needs to chose which side of the scale he really prefers
7-9 or 9-11
and 911 is Formula ideally
can always opt for the middle ?? 8-10 (many options)
Mistral 137 or jp super light wind. Jp slw is a lot floatier and enough deck area to carry big rigs and it still gybes awesome.
I would look at two boards if possible, better two second hand than one unsuitable. Either 70cm wide 115 litre slalom board that you run a 7.0m and 7.8m on, and a JP super light wind or similar with an 8.6m and 9.5m. Or 70cm wide 115 slalom board with a 7.0m and 7.8m and a formula board with a 10.0m and a 11.0m.
since it has NOT been mentioned yet, i will "do the needful"
the ONLY board I would use with sails from 7 m? to 11 is a longboard
i can do this comfortably on my Mistral Equipe 2 XR carbon sailboard
joewindsurfer.blogspot.com/2016/04/mistral-equipe-ii2.html
now there is an Exocet and the SB Phantom(s)
however, these boards are $4000 new and $2000 used if you can find them
AND Starborg is only recommending 6.5 to 9.5 ...
Select to expand quotejoe windsurf said..
Formula boards have become short and straps are even more outboard than the above boards (8-12 range ??)
the above boards are more 8-11/12 and not 7-11
7 m² sails tend to be used in better winds and thus rougher water - not ideal for wide boards
I have used 7 meter sails on 80 cm wide boards, but that is about the limit
and 10 meter sails are about the limit for those boards as well !!
typically ideal sail range for a board is no more than 2 square meters and NOT four
like 6-8, 7-9, 8-10, etc ...
JP SLW is shown on their site flying around with a 6.7 sail!?
Sebastian Kornum is in a great vid on a silver SLW with8.2 twin cam sail. Short runs with gybes for the camera.
lovely ...
however, I will stick a large sail on my longboard in light winds
when the wind picks up just a little more, I still prefer the JP SLW
and i do not edit my films as nicely as you do
as I speak German, I can almost understand what you are saying in your film(s)
please disregard my fear of footstraps 
I got rid of the Viper and bought a starboard carve 161L instead. That will carry my 11 m2 sail. Everyone have advised against it but I will have none of that you hear! *shaking the fist like Homer Simpson*
am happy u r happy and sorry to turn you into Homer pounding fists
please let us know how it all turns out
when I had an AHD FF 160/79 with 52 cm fin ... found it okay with 10 meter sail
but I like that sail MORE on longboard or JP SLW (with bigger fin) - that's just me
when riding that AHD board with a 7 meter sail, I used a 40 cm fin and found the ride rough
(would rate AHD as ideal sail range 7.5 to 9.5)
again, please let us know how that works out for you, but don't pound on the board 
I reckon you've made a great choice SS, width is your friend. I use a 154 litre freeride board myself with sails from 5.5 to 8.5 regularly and use a 10m occasionally. A couple of my mentors have recommended that, for light wind use with the big sails (8.5 and 10), I use a big (55cm plus) slalom/race fin so that's what I'm trying next. My board's standard fin is a 52cm freeride shape which is great, but a race fin will allow it to point upwind a little better and a big race fin should help get it planing in light winds. The hardest part for me is tracking down a big fin in powerbox, tuttle might get you a few more options.
A 50 cm freeride fin came with it so that should be good for the sails and bad for the beach starts.
