Yeah I've seen the fiber optic irons but never used them, they look interesting. Would you say whether either the red or green give better visibility than the other?
I do want to play around with a red dot too. Any brands of red dots you personally like?
Red or green is entirely up to you. The thing about fiber optics, as mentioned by someone else in this thread, is that it's not baked into the sight, it's replacable. You cut out the one that's in it, insert another one, melt the ends and you're all set.
Playing around with red dots is EXPENSIVE. Go shoot someone else's before you commit to buying one. Personally, I have Burris FastFire 3's on a couple of my 22's, and Trijicons on some of my centerfire handguns, (9mm, .45ACP and .357Sig). The Burris sights aren't too expensive, but they're way too fragile for anything but a range toy.
I've got SROs for my range toys and RMRs for my carry guns. The SROs have larger glass and consequently the dot is easier to acquire, (for me), but they don't seem as durable to me as the RMRs, (opinion - not backed up by scientific study). They've got excellent warranties and I really like them, but an RMR on sale is still going to cost you 400 plus. I've got them on Glocks - the optic cost more than the gun in some cases.
I've heard very good things about Holosun sights, handled a few guns with them, but have no experience shooting them, nor any valid opinion regarding their durability.
I dithered a long time before I put RMRs on any of my carry guns. Life has shown me that things go wrong at the worst possible time, and having no sights on a self defense weapon would suck. Most people who put optics on their carry guns back them up with iron sights.