well pickups can still get pricey. and if you dont know what you’re doing, it might ruin the sound more than anything. i wanted to do the samething, but then i bought a strat instead haha
you can get a good strat for cheap. those Made in Mexico ones arent bad.

Humbucker

Texas Specials

Upgrading the pickups may help a little, but I would have my doubts how much (cost / benefit ratio).

For blues pickups a lower output single coil will be better. Cant really recommend any, I have a set of fender vintage noisless pickups which do me well.

If you see yourself wanting to get another guitar sometime in the not too distant future, then its probably not worth the investment as the cost for a decent set of pickups will take a brave chunk out of a new guitar.

One of the things about blues tho is it sounds great, if not better on cheaper, twangier guitars.