Congrats on the gear.
OK. Recto series amps are not known for their 'liquid sustain'. Many who have or do own recto amps have complained about this. They're more a rhythm players amp and they do very well in this department. It's the design of the amp. Having said that the recto amps need help to get a great liquid type solo tone.
Push the front end with an OD pedal. 808's are very popular for this but I think for a more liquid type of drive, an OD pedal that provides a more compressed signal is required. Maybe check a RAT pedal (I think the 'You Dirty Rat' pedal will be good (haven't checked it out). Try a compressor pedal after an OD, too, with some light compression if you want to. If it sounds a little 'thin' or the tone suffers because of a single tone control on the OD pedal, place an EQ pedal after it; it'll do wonders.
Alternatively cascade two pedals. I found an OD-type 808/TS9 pedal into a Wampler Pinnacle can provide some great solo tones. You need to watch the first pedal's gain and level, then the second pedal's gain and level and thirdly the amps gain. You can't just turn everything 'up' because you'll end up with a muddy signal and uncontrollable feedback.
Also, try placing an EQ pedal in the loop if you want to tighten the amp further or have better control of the tone shape. This is very popular amongst recto owners; pulling down the 200~250Hz slider a few dB to clear the mud. Of course, your cab/speakers will play a big part in your tone.
I own a rectoverb amp and have many OD/Dist pedals. My current favourite is a Marshall Drive Master into a Wampler Pinnacle. I also have the Wampler Plextortion which is very good too. I have an EQ in the loop and I need/want to place two EQ's out front before and after the pedals.
I've also had an MI Audio Blues Pro pedal driving the Wampler Pinnacle and from memory that was good. Whichever way, the recto amp needs help. If you can get a hold of a few pedals, experiment. What may suit me may not suit you so take my advise as that - advise.
Also, and I stress this, if your playing is sub-par this amp will let you know about it. It will force you to play better, which is a good thing. You cannot hide behind a super-saturated tone, like some of these super-saturated-high-gain-highly-compressed-sustain-for-days presets in modelling amps/stomp boxes. Welcome to 'real' amps. It's a huge learning curve.
If you want to learn more about the recto amp jump on this site http://forum.grailtone.com/
and navigate to the areas that interest you and that apply to you. I'd advise to read about the recto amps in general (single/dual/triple amps) to get a better understanding of the preamp section and what people do to overcome issues. They'll apply to your preamp as much as their preamp (even though they may be heads/combos). Changing preamp tubes may help you, too. Check the grailtone site to see what others are using.
For your power amp, it'll run pretty clean. The recto amps have a fairly (and reasonably) clean power amp section as most of the overdrive tone comes from the preamp section. I'd assume the 2:90 is the same. If possible, try EL34's. They'll compress the tone slightly (compared to 6L6's) give a slightly higher boost in the high mids and slightly less bottom. Experiment with tubes.
Have fun. It's a whole new ball game.