Brian,
Hello & Welcome to the Forum!

First of all, they're YOUR trains and it's YOUR layout,  so run what you want as you want to.
(if you have folks who would rather you did it some other way, smile & say "interesting possibility" then continue to enjoy your trains.)

Second, this is a fairly new forum, so you won't run into the "use the search, this question has been asked & answered a thousand times.  If you do, please let me know and I will have a chat with that individual.(Global Moderator Comment)
We do have a few members that I would consider to be some of the most knowledgeable persons in the model train world ,but I believe that the bulk of the members are new to model railroading, (newbies).

I personally am an Analog Guy, so my knowledge of the Lionel Cab 1L/Base 1L system is almost non existent.
Hopefully someone will chime in with with knowledge/experience with the system.

Your track/layout, I would suggest that you do your basic connection of the power to the track. Then take what ever locomotive  you will be running, put it on the track and let it run.  Take your multi-meter and go around the track and check the power that is being supplied around the track (while the engine is operating).  IF you find spots where the power drops, you may want to add some feeder wires to those points, to insure that your track is powered equally at all points.

As to whether any other manufacturers will operate on the system, MTH & K-Line by Lionel are the only two that I can think of that may work with the system.  Again, hopefully someone with more knowledge of the system will chime in.

If you have any questions, please ask them! Someone else may have exactly the same problem with their trains, but are afraid to ask, so you'll be doing both of you a favor.  If it comes down to it, if you or anyone else on the forum has a question they're reluctant to ask publicly, either PM me here or send me an email to the email address listed in my profile and I'll try to answer or find an answer to your question.

Happy Rails!
Dave