G-FORCE to start ACRO (only safty over Water) recommend?

hi guys i could buy a g-force 20m² in top condition. i just started paragliding but i trained alot this summer on gerlitzen ( living near there) so can the siv WO and sat. can u suggest me to buy a g-force? i can fly and train a lot over water.

whats up with that weight categories? a 20m² glider up 120 kg startweight??? in fact i had to take the 15m² with my 75kg bodyweight????
which size is recommend there for my weight?

now i flew the gangster.

gretz