I have 2 1010lt's in my current setup. I got the first one about 8 years ago. I got the second maybe 4 years ago. I tried the mic pres the day I got the first card, and I haven't used em since. Also, they don't have phantom power, so you wont be able to use condenser mics.
As far as the connections, right- they're rca. You can get a cheap 3' snake that has 1/4 unbalanced on one side and rca on the other side- you're gonna need cable anyway to connect to your preamps. There is no difference between 1/4 unbalanced and rca- its just a connector- its an unbalanced connection either way. The purpose of balanced connectors (i.e. 3 conductors) is noise cancellation. Being that I have a short run between the preamps and the 1010lt, this hasn't been a problem. So, for some people, rcas are a turn off but i think thats more a perception issue than an actually functionality issue, especially in this price range. For a more expensive unit, I'd expect balanced connections.
As for preamps, you're gonna need one for each mic you want to use. I have a Soundcraft M8 mixer which has 8 mic preamps with direct outs on each channel- that feeds one of the cards. I also have a PreSonus D8 that feeds the other card.
Keep in mind that the vast majority of budget mixers (i.e. under $1000) WONT have direct outs on each mic channel. Having direct outs is really contrary to the purpose of a mixer if you think about it- a mixer takes multiple sources and mixes them all together. You can use the insert channels on most mixers in kind of a "cheater" fashion by taking a 1/4 cable and inserting it only half a click in. On most mixers, that will get you an unbalanced signal just after the preamp and before the EQ and effects sends. While this is usable, it isn't exactly a solid connection and you lose the benifits of actually using the insert for its intended purpose and you also lose the option of using your eq if you so desired.
I would also say that the 1010lt converters aren't stellar. In fact, it'll be my next major purchase to replace these cards when I get more money and more need (my studio is all hobby, so it doesnt really generate any income).
So... for what you'll pay for a 1010lt (~$200) plus what you'll pay for an 8 channel preamp (~$400), you'd probably have an easier time getting one of the many 8 channel firewire or usb interfaces that combine the interface and soundcard functions into one. A Motu 8pre, Presonus FireStudio or one of the many other offerings out there...