I used weed trimmer line to clean out the gutters without worrying about wire causing damage. Run it through and pour some water down the drains while wiggling and rotating the trimmer line. Once water starts coming ou the bottom, run the line all the way in and out several times while pouring water down the drain the whole time.
Getting Toyota parts is almost always worth it. I don't care for stock cruiser seats, so I make a few exceptions (and Toyota diesels are out of my budget).
Take your time, try to support the vendors on this forum when you can, but if you can save up for a big order, buying genuine Toyota parts from Amayama.com or the other overseas OEM parts vendors is one way to save a lot of money if you're not in a hurry. Read their import regulations carefully though, I split my order into a few smaller ones to keep each order below $200 (including shipping) to avoid the cost, expense and hassle of needing an import broker. In the ends after shipping I still saved over $250 by buying from amayama.com but it's not a quick way to get parts.
Toyota OEM u-joints are nearly the same price overseas as they are stateside and the widow runners are half price over there.
If you're not hindered by a deadline then use the money you would have spent on labor to go towards the tools you need to work on it and fix it up as the budget allows. Spend the money to get the right tools and if you need an odd special tool, there's a decent chance someone on this forum has it or knows how to make it fairly cheap.
If you always wanted one growing up, keep it. Now that you own the vehicle you always wanted, you'll regret it often if you sell it.
I say replace the seat with a set from a junkyard and enjoy the truck, and get a new steering wheel cover as soon as you can. I'm sure your budget won't break over a steering wheel cover.

And you'll be extremely surprised how much of a difference pressure washing the carpet will make as others have suggested.