You could go the cheapest way and convert your 4 x 12 to stereo although it would only be 60w per side. I have slant split stacks, 2 with boogie celestion 90w speakers and one with celestion 75w which I run in stereo (so only one cab to lug). The boogie celestions are a little toppy (like most things boogie) but being 90w speakers gives me 180w per cab (hard to blow up). I'm reasonable happy with them though the split stacks are a bit "beamy" so if I'm using the 2 boogie loaded cabs I often turn them on their side. If you want to load some 2 x 12 cabs you could considers these (https://www.melbournemusiccentre.com.au/lorantz-12-75w-8ohm-speaker-57136.html) or similar (they have other models but the 75w would be the go IMHO).
I bought a pair of messa P112s for my bass rig (so 1 x 12 plus tweeter which you can turn off). 300w 8ohm cabs. They sound great for guitar/bass/vocals... I leave the tweeter on an use the cab sim outs on my MP2 for guitar. They are expensive cabs but really impressive and very well made. As they are bass cabs they would really suit drop tunings.