I've had exactly the same situation in my band. We recently ditched our rhythm guitarist and when the lead player solos, it started sounding a bit empty. My first experiment was with a Digitech Bad Monkey. Don't lose much tone from this and it isn't toppy when adjusted right. Then had GAS for something else so got a Way Huge Green Rhino. I now have what I want. I didn't want loads of distortion or fuzz but just a bit of break up and both these pedals do the trick. I'd be happy to lend you the Bad Monkey or you could have it off me for £25+ P&P if you wanted. PM me if you like.