Welcome to paintball mate, i'm new too really hehe, but i might be able to help.
Yeah, I would definately get a nice mask with a thermal lense, i used to fog up like a bit*h on rec ball days with the rental masks but i got a 2nd hand pair of events and they're brilliant. Light, don't fog up, and look pretty dam sexy lol.
About markers, i myself have just got a pmr an would thorougly recommend one. For £150 it's a great marker, and for £10 more than an ion I think it's well worth it. They're easy to look after, look tasty, easly upgradeable and more importantly they RIP lol. But i all depends on how much you're going to spend. Also like other people have said,you can pick up a 2nd hand pm or dm on this forum which is a very good choice aswell.
The easiest thing is to get to a shop and look at them, you'll find you probably had any misconceptions about some gear and you'll almost definately will find things you like, and usually more than the gun you were eyeing up before. Also getting to a walkon and renting is a good idea as i did that a couple of months ago before buying my own kit, but not all sites do that just give them a ring and i'm sure they'll sort out something for you.
I'm pretty new to paintball too and im not sure if I totally know what im going on about before anyone says it lol
, but i hope it helps mate.