New halyards for an S2 7.9 what to get

I'm not a nationals level competitor, but I want to buy "decent" equipment for my boat. The boat has what appears to be 10+ yo halyards (and they are green from growth, as well as chafing really bad) they are obviously in dire need of replacement.

Anyway, I don't have tons of $$ to spend. I think I lucked into VPC (someone ordered the wrong length standard for a tall rig) on my Capri 22, and the prior owner did the halyards on my Capri 25, so I really haven't had to actually plunk down money for halyards myself yet.

So some info, the S2 association said that the boat originally had 3/8" basic double braid on it... It looks to me that my existing halyards are 3/8" double braid, probably XLS yachtbraid by the looks of it. http://www.s279.org/specs.html

My thoughts were to go smaller diameter, to 5/16 (as that was what I did on my Capri 25, with a similar sized mast and gear) but go with VPC or perhaps MLX...

So my question is... will any of this matter... should I just save money get the XLS 3/8 yachtbraid, or will 5/16 VPC be a better/lighter less stretchy alternative... would MLX be better, or another option be infinitely better for halyards?

We basically beer can race 8-10 times a year, under-crewed (2-3) in flat inland lake water with average winds 8-15 knots. We're a pretty informal bunch, but we have up to 6 S2 7.9s coming to the start line, they too are under-crewed but well sailed.