Might as well not do it then! Buying a useable 78/79 Dana 60 will eat up close to half of 2000 bucks, then you'll have to rebuild it and probably gear it and lift/axle swap/gear the rear to match. You can drop 2000 bucks in a Dana 60 without even trying! When dealing with an axle that's almost 40 years old you'll want new rotors, pads, calipers, more than likely wheel studs, wheel bearings, deals, u joints, lockout hubs, kingpins, and maybe even diff bearings.
The front driveshaft will run you around 300 bucks because you'll undoubtedly need a 1350CV shaft, it's a pretty steep driveline angle depending on how much lift you wind up with. Depending on what kind of time frame you're going to work with, you could make your brackets or just buy a setup ready to do. DIY4x and Off Road Design both make very nice kits that are around 500 bucks and well worth it for the quality and strength of their parts vs. your time and energy to build the same thing. Then you'll need crossover steering and a steering arm...probably a new tie rod as well. Somewhere in the mix, you'll need new brake hoses as well. Not to mention a set of 8 lug rims and some tires.
It's not a "cheap" process, but it can be done sparingly if you can find some good deals. I have probably 6000 in my setup and I got some smoking deals on big money items. I cashed out on the rear axle...sold my stock 10 bolt for 300 bucks and bought an AAM 11.5 for 300 bucks with 4.10s in it. I scored the front axle for 850 in pretty good shape, but they regularly go for 1000-1200 by themselves. The good thing about an 88-99.5 Chevy frame is it's wider than a 99.5+. My frame is only 37" wide, whereas yours is 39" wide. That means you can use a less sought after (read: CHEAPER!) 1980 and newer Ford Dana 60 with 36" spring width.
You didn't mention if you wanted to use leaf springs or links, but for no more than you want to spend, you're definitely not talking about a link setup. A leaf spring setup with either use 73-87 Chevy front leafs springs (47/48" long) or rear leafs from the same era 1/2 ton (52" long). The 52s will flex more because they're longer and they also net around 4" of lift when used in a front suspension setup.
Oh...you'll need some exhaust work to clear the front driveshaft.
It's all about research. If you can mix and match and find stuff on the cheap, you'll be there in no time. I'm not trying to scare you off, but it's kind of in depth. I wouldn't go back and change anything about doing the SAS on my 99 Silverado for anything. You also have a much easier truck/platform to start with as well.
http://diy4x.com/cart/index.php?route=product/product&path=24&product_id=185
http://offroaddesign.com/catalog/88-98SolidAxleConversion.htm
The ORD link has lots of pictures for reference and some good information as well. I did a lot of small things that added up in the money department. My ABS still functions, most of it looks stock, and I did an SYE on the transfer case. I'm using an NP241 just like in your truck. They work very well.
