Yeah man, I hope for your sake you can pin down that new job. PL1 is, as you know mono, and basically ambiance. Normally, a good upgrade path is to put decent speakers on the entry level AVR, then upgrade the AVR later. But in this case I feel the opposite. While your speakers could certainly stand to be upgraded, I think(and you too?) the AVR is the bottleneck. If you can, I think you should find a decent AVR, and focus on speaker placement and setup. A4L as linked is a great place to get a nice current AVR on a budget.
Can you post a pic of the back of the surrounds? A shelf would be easy, but if they have keyhole slots, that’s even easier.