I use a community darkroom about a mile from my home: http://pcnw.org

They have three film sinks, including one specifically designed for tray-based large format black and white film processing.

They also have 18 enlargers, including a monstrous 8x10" enlarger: http://pcnw.org/facilities/black-and-white-darkroom/

I bought Tetenal's C-41 kit last night with the Portra, and plan on developing there, as they also have filtered water, film dryers, and Photo-flo :)

I've looked into these processes years ago but backed off because they seemed to require some really stringent temperature control. Is it no longer the case?

In general I'd say the C-41 kits are relatively simple for someone who's accustomed to B+W development. It comes down to being sure the chemicals are at the proper temperature and that agitation is even. There's much less tolerance for variation compared to B+W but it's still well within the reach of a diligent amateur who focuses on reproducibility and good lab skills.

The main requirement is a temperature-controlled hot-water bath for warming the chemicals, which are relatively easy to construct with some creative use of aquarium equipment. Buy yourself a digital thermometer from Amazon to verify your chemical temperatures (you should have one anyway for B+W development).

You may also want to consider a rotary development instead of hand agitation. If you can find a "roller base" unit, you can just place a standard developing tank on the rollers and it works fine. I love mine for B+W development too. Works like so.

https://www.youtube.com/watch?v=60rYmqkyfDg

E-6 is a little more complex than C-41 and I do not recommend the DIY kits in general. The DIY kits are a simplified 3-bath version of the full 6-bath process and has negative consequences for quality and long-term stability of the resulting slides. Since it's more difficult and the finished product is inferior I recommend just getting it commercially processed.

You can send it out at most supermarket photo centers, just mark "E-6 Process" on the "special instructions" box. It all gets sent to a processing company (often Fuji) and they know what to do with it. Nobody does in-house ("1-hour") processing anymore, sadly.

Thank you, looks like little has changed since I checked last time.

I live in a relatively mild climate and B+W development usually means measure the temperature of tap water once and go with it for the day. For C-41 it's also a bit harder to keep things at 39C which makers a larger gradient against room temperature than 20C, but in the end I suppose it's not too hard with a water bath.

It is mostly the case. Some of the kits are designed to be more manageable at home--not requiring lab-level controls. But still a little fussier than b&w, no matter what. Personally, I haven't looked into too much, because I am color blind and have a hard time with the printing. I stick to b&w now mainly.

I just traded two Mamiyas for a Hasselblad 503. The Mamiyas are fine, but I have too many systems to feed now.

The printing is the fun part, anyway.