JP Australia RWW 83ltr - advice/recommendation pls

Hi Guys. My first post on the forums at Seabreeze. After 10 years out of the windsurfing game I've recently bought a decent second hand rig with 3 sails: 5.0, 5.4 and a 6m

I've been surfing since I was a young fella (I'm now 40) and used to be rather competent on a windsurfer. I jumped on a mate's board a couple of years back and it was like riding a bike... first run I managed a full carving jybe, a few chop hops, water-started with no problem and even managed to get a couple of duck gybes in after an hour or so.

I sailed mainly in Botany Bay, Sydney, Jervis Bay as well as some wave sailing. My last board was a Waitata II slalom around 110ltrs from memory and a 70 ltr wave board that sunk up to my waist in lulls.

I've noticed how much has changed in my absence, and I'm not really sure what sort of secondhand board I should buy. I like sailing in choppy stuff and want to pop airs and stuff, and also want to do some wave sailing at Cronulla in Syd once I find my sea legs.

I'm currently looking at buying a secondhand 2007 JP RWW 85ltr for $400, but I'm not really sure how it will hold up in around 20kts on Botany with my 85kg frame. I really dont want to spend more than $800 on my new (secondhand board) until I find out what works for me in these new designs.

Does anyone know if this is a good board. Will it keep me planing in 15-20kts with a 5.0 or 5.4 wave slalom rig?

I've read this board is really focussed on wave sailing, but I like the look of the outline and dont mind sacrificing top-end speed for something that's going to be versatile on Botany Bay and in small waves.

Looking forward to your advice and feedback.

Oh, one more question... I used to use a seat harness and hated how waist harnesses would ride up. Are these still around and would you suggest I go with one these days, or have the waist harness got heaps better.

Peace
Nige