Mass application of values/names through SQL?

Let me explain my store a little bit... we sell furniture to K-12 schools. We have a goal of getting about 75 vendors into the database. Right now I've got 7 in, and that's 2000 products. There will be many, MANY more products by the end. Probably somewhere around 25 or 30k.

The thing is, all the different vendors have different seat and frame color combinations and certain other options. I can't just apply my attributes across the board by category since not all of a certain type of item are by the same manufacturer, and I can't really go item by item either due to volume.

Does anyone have a SQL query that will copy attribute values based on a list of product numbers, product ids, manufacturer id... something like this going?

I know a little SQL, and could probably work one out from scratch over time, but I'm still not familiar with all of the tables in ZC, especially not the attributes ones... and some basic framework from someone would help a lot. My other option would be to try and use the EasyPopulate attributes table... but I'm not sure of the best way to do this in bulk with that, and I'm pretty sure I'll run into the problem of hitting the column limit in Excel that I've read about...

Advice would be greatly appreciated.

My other option would be to try and use the EasyPopulate attributes table... but I'm not sure of the best way to do this in bulk with that, and I'm pretty sure I'll run into the problem of hitting the column limit in Exce
Unless you are adept and know the Zen Cart structure that you need to get the vendor information into EP is probably your easiest bet.

You will have to break this up into blocks due to the limitations you mentioned, still more efficient than one at a time

I've downloaded EP and have played with the pro version. As far as I can tell, there is no support for product attributes - only the products.

Also, it looks like you can only drill down one category level.

Also, I'd like to put products in more than one category, and I don't see how you can do this with EP. I placed products in two categories on the excel file, but they only showed in one of the two.

There is very little documentation on this, so it's hard to tell the scope of the program.