Fixed gantry design table question

I am working on a fixed gantry diy build. I have a 66” gantry (i beam), with just over 52” of ballscrew travel . Vertical legs mound under the i beam, so im looking at a table width of 48”.

The original plan was to use the conventional two linear rails, spaced around 32” apart, screw in the middle, table on top. I’m kinda worried about the table deflection in the center, as it seems that likely were a majority of the work will be done. I was going to do a mic 6 table, but that stuff is getting Real expensive, seeing as i likely need it to be around 1” thick, 48”x48”. I can make some kinda boxed in table with 1/4” plate and a bunch of 8020 i have laying around , spoil board on top.

most of my work will be wood, plastic exc, but i do the occasional. 1/4” aluminum plate. (Currently ,On my existing smaller machine ).

Any suggestions on a decent table build i dont have to drop a grand on? Does using 4 rails on the table make any sense? . This would also be expensive as they are going to be quite long.