Hmm, well... know that snakes love to be cramped. Seriously, the tighter the better. If the snake is an '09, then I'd say you'd be fine with the "small" size of hide. If you're really worried or something, just get a small and a medium so that the snake has a choice. (just make sure the smaller one is in the warm side of the cage)
Then again, I don't know the exact size of the snake soooo. For all I know these could be early '09's and be getting a little big by now. XD
Aaaaand, the first lamp is what I'd recommend, just because it's always what I've used (the 5.5 and 8.5 both), and really they're... great. Then again, it's a lamp. So what can go wrong with that? XD
As for the thermo... well, the digital thermo's batteries will last... a long time. Like months. Buuuut. If you're tight on cash (and if you are, I do understand. Just don't get a dial one), it's better to go with something than nothing.
As for the hygro... well, yeah. That'd work fine. Honestly... if you can't afford one right off, don't worry about it. Just look over the snake each day to make sure he's doing well and give him fresh water each day or so (which needs to be done anyway). Corns aren't picky about stuff like humidity (unlike ball pythons <_<)... so you should be okay.
As for the water bowl... well, you don't want it so deep that the snake can't get out. But neither of those, from what I can tell, are
that deep... so I think you'd be fine with either or.
Then again, I have a dog dish in my boa's cage and Glad containers in my corn's and king's cage. >_< XD
In other words, whatever works.
As for the lid... yeah, that works (I think it's the exact one I've got). And. Clamps are a necessity. Seriously. I've got 'em on all my cages. Because a snake, even if it's that small... has insane strength. And he'll push up the lid and escape if you don't clamp it down. Seriously.
The cage carpet is good, though if he poops or anything on it you have to clean it out (unlike newspaper or aspen which you just scoop out and throw out). That's mainly why I stick to paper or sometimes aspen. (corns especially love the aspen stuff. They... make tunnels and stuff, which is why I'll once in a while give it to them)
Newspaper works great though, and it's cheap. (all of my guys have it at the moment)
The thermo... eh, I dunno. Just set everything up and then see what the temps read, and feel the heat mat after a few hours (feel the actual glass) and if it's too hot to touch then... it's too hot for the snake. Always remember, you can disable the heat mat (like I have on the king's cage for now) and stick with lamps until you get that thermo, because when a snake is that small... well, it's pretty easy for them to dry out and burn if it's too hot. o.o
Also, I don't know if I've told you this... but depending on your room's temp... stick with 75 watt or lower bulbs. You shouldn't need more. I'm in Michigan, and I've got a 75 on mine right now and I gotta be careful it doesn't get too warm. o.o
Also, shopping lists ftw yo. Seriously, I love being able to help a fellow herper out.
Any more questions just ask away. I'll try mah bestest to answer 'em. ^_~