Sucks to hear about your accident, hopefully it was minor and nothing other than bodywork is needed. BTW..periods and commas would help in making your posts a little easier to read...hehe..it's all good.

Anyway, poly urethane is the preferred material of any body kit. Wings west uses it, their kits are very well made...Fiberglass is stiff and does crack easily...poly urethane on the other hand gives a bit if you scrape or scratch over things...so that's definitely the way to go if you can. Some kits are only made in fiberglass because it's much easier to mold. The more "complicated" kits are typically made this way because Poly U is hella expensive to mold...also another reason why poly u kits are typically more subtle and smooth looking.

OEM bumpers are made of ABS plastic. which is harder than Poly U, slightly thinner...but as far as safety...makes no difference. Aftermarket bumpers are typically made of urethane..which is good too, but not quite as good as ABS plastic, hence the cheaper price. But honestly, for the purpose that a bumper serves (covering the styrofoam and actual frame of the car that protects you) any material really is good enough...I'd go for an aftermarket bumper or body kit. Good luck.