I've always thought the Rat into a Marshall is one of the best rock sounds ever. Rat's also do low-gain amazingly. For the longest time I avoided rats, but then figured out how to use them and now its my main OD.
Rat can get you both good low gain and high gain, and even fuzz sounds. I would get a digital delay like a DL-8 or DD7 instead of a chorus for leads. But honestly, its better you invest in a good amp, perhaps a combo.
Everything Mark makes is gold.
I had a Revelation Superbass and Superlead, a Pharaoh (which I regret selling), played an LSTR extensively, and currently own a witch burner. They are all really damn good.
Based on what you're looking for, I think LSTR might be the best option - or even better...
Had both - still have the Soothsayer. The Soothsayer is much clearer sounding, more headroom, and lots of control options. That being said, the modern Rat is very good too, especially for a dis/od for less than $100
Version 1, in great condition, comes with box and paperwork. Removed velcro on the back so theres a little bit of residue.
$90 U.S, including shipping to anywhere in the US or Canada. For other places, please contact me. Paypal only. Gift preferred. :aok