I'm 94kg (damned winter coat!) 200 cm and have recently started riding a BWS Drifter 5'8" with straps. I think I could do with a tad more bouyancy, i.e. a 6'1 type board but the drifter's fun factor makes it easy to forget that. I just went straight into the surf with it as I figured there was no point delaying the inevitable. If you're in the surf already it's not a big difference besides having to go toeside. Watch out for the shallows, or you'll tear your box out

Just make sure you're well powered up to start off with so you don't get stuck between sets and also to make toeside a bit easier.
Another tip is to only take your SB to the beach with you, no backup (backout!) plans. It's pretty easy to convince yourself that the SB isnt the right tool for the job right now.
Adding the SB to the mix for me has given me a quantum leap in enjoyment to a hobby I thought was already pressing all my buttons. The word spiritual might have been used when it all clicked in place for me but you know man, peace.