Some later model 486 and AMD 5x86 boards had both PCI and ISA, but those could be a tad wonkey sometimes. For a general purpose starter/tweener, I would recommend a generic ~Pentium 1 200mhz motherboard. I would also recommend that it be a generic AT or ATX form factor, not some proprietary manufacturer-specific board. There were also AMD K6 boards in the AT form factor.
I'd also recommend avoiding anything with an integrated Dallas/Odin clock battery. Get something that uses a standard easily replaceable coin cell battery.
You can also find boards up to, I think, Pentium 4 and Athlon XP with ISA although some of those have known issues and usually only have one ISA slot.