BIC, NSP, Southpoint – great beg/int makes. My mates (are just standing up for short periods, about 11-13st, average/average+ fitness, 40ish yrs old) love the Southpoint 8f6, they find NSP 7ft6 is just a bit narrow/wobbly/harder to catch small (1ft-5ft) mush waves on and they no longer like the soft Swell boards that they started on.
I'm a one board man using a McTavish surftech[see also tuflite] (much lighter to carry, but more expensive to buy), 8ft 6, (50 yrs old, 13st, average\average+ fitness for age), can stand and turn (ish). (* I actually have 2 other boards but the 7ft 6 requires such effort to get going (and stay on)that I can't be bothered). (Poss for sale mint 7ft 10, berks, McTavish suits me better)
There's probably an equation somewhere, IMHO, the lighter, fitter and more skilled you are the shorter you can go and get the same end result.
Certainly try some and get a feel before purchase. Just ask other surfers, I managed to do that with quite a few.