You're going to need a lot of patience and a lot of gold. I know you said the latter wouldn't be a problem, but it's going to be even more cash than you think, most likely.

I'm halfheartedly working toward this myself, but here's the deal: You're going to need to grind every base faction, Alliance or Horde, that you can get to Exalted, except your own (but you'll probably hit it along the way). Then you'll have to have enough gold to buy all the mounts, slow and swift, and that's just for ground mounts. You'll need to find people willing to grind ZG with you if you can't solo it, and run Stratholme over and over. You'll need to wait in hours-long AV queues so you can get enough tokens for both all the PVP mounts (30 for each one = 150) and your AV faction mount (50). Not to mention grinding the other battlegrounds.

And that's just vanilla.

You'll need to grind rep like a madman in outlands. Netherwing, Cenarion Expedition, Shatari Skyguard, Mag'har/Kurenai. You may also need to pay off a friend of the opposite faction to sit in Halaa for you for hours while you bomb the crap out of them. (This is what Death Knights are for, am I right?) And flying mounts cost a lot of cash. The Netherwing drakes run about 200g apiece, but the Cenarion hippogryff is 1600 (iirc, I haven't gotten this one yet). Then there's the drops from Kael'thas -- good luck with those, though you could probably find other people willing to run them with you since they're popular. And make sure you buy all the regular flying mounts from your faction vendor.

Northrend is a bit kinder than Outlands, but the deadline on a couple of mounts is ticking. If you want the Black or Plagued Proto-Drake, you'd better get on the achievements for them fast. A lot of the others are luck -- Time-Lost Proto Drake, Green Proto-drake, etc. And others are grinding. Run H-COT-Strat a thousand times, H-UP a thousand times ... oh, and wear your Wyrmrest tabard while you're at it, so you can buy the red drake. And make sure to buy mounts from the vendor in Dalaran, and save your stone keeper's shards for a black mammoth.

Then there's all the holiday mounts...

If you're a Paladin or a Warlock, you'll have a bit of a bonus, since their class mounts count toward the total.

I'm only up to 41 myself, but like I said, I'm just doing this halfheartedly. I've gotten all the Horde faction mounts and a few Netherwing drakes, a couple PVP mounts, and a couple miscellaneous drops. It just takes patience, mostly.