Finally, after nursing my MSI Z77A-GD65 and i7-3770 for probably over seven years, I bought a new motherboard, CPU, RAM, and a Noctua HSF. The i7-3770 and DDR3 1600 weren't cutting it for editing large photos any more. Plus the lack of PCIe lanes is a bummer. I opted for an older Intel system rather than a new Ryzen or Intel platform because I couldn't get anything with lots of PCIe lanes for cheap.
The Motherboard
A SuperMicro X10SRA. Bought new from Newegg with substantial discounts. A little over $200 shipped.
The CPU
Intel Xeon E5-1650v3 6 cores, 40 PCIe 3.0 lanes, and 4 channels of DDR4 of Haswell goodness running at 3.5ghz. Used. $95 shipped.
The RAM
Four 8GB DDR4 2400 registered ECC Kingston sticks for total of 32GB. Used. $100 shipped.
The HSF
Noctua NH-D9DX No idea if this is sufficient. If not, I'll add a fan too it.
Parts should all be here by Friday. I might get a different LGA 2011-3 processor later, maybe a v4 model which supports faster DDR4 RAM.