Good idea with the jute ,mate, nice one
I've used spun poly and find it OK, nice to tie with and to use .
If you're making your own nets you can afford the best so go for a reputable supplier (Agouti or Torchy)both are very reasonable . Don't be tempted with the bottom end of the market stuff it's crap, it's well worth spending an extra couple of quid a spool on decent gear .
ATB