Don't know if I want one with a built in preamp but some EQ control might be nice.
Important distinction: There is a lot of "grey area" around the way manufacturers and consumers use the terms "DI", "EQ", and "preamp". There is often technological/electronic overlap between them, and a great many products out there use the terms misleadingly, or at least in a simplified way.
The vast majority of EQ's are active devices; a preamp is an active device; a DI may be active or passive; a preamp puts out a buffered or boosted signal, but may or may not be able to drive a power amp; a DI may or may not have a line-level output in addition to the XLR main DI output. So you may get some random combination of these elements, designed to different functional specs, with each model of so-called "preamp" or "DI".
Take the Sadowsky outboard preamp/DI (which incidentally would be a great choice for you based on what you're saying): it is an active device, so it's technically a preamp, but I don't think it's able to drive a power amp. It features a two-band boost-only EQ and two outputs, a DI and an instrument level out.
However most DI's (that are marketed as DI's) don't have EQ or other tone shaping. Another consideration is whether you want the onboard tone shaping to pass through the instrument level "thru" output to your amp. The thru out on most DI's is "dry", i.e. identical to the signal going in. But there are a few like the Sansamp that have an "effected" instrument-level out as well.
Then there are a few DI's (that are marketed as DI's) which have a +4dBu line-level output in addition to the DI out, and thus are able to drive a power amp. Most of those don't have EQ though... and the ones that do are marketed as "preamps" that feature a DI.
