you may want to play your acoustic for a little while before going in, and you don't necessarily have to buy tomorrow, do you ?
You may also find that what you play in the shop will sound very differently at home, so play a few, and just a simple scale, chord progression, or 12 bar blues solo is ample.
Another thing of importance is the scale length of the guitar, the strat and tele are 25.5 inches while the Gibsons are 24.75 or thereabouts, you may prefer one over another for that reason.
The strat is also a good guitar to practise on unplugged because it has a chambered body.
Also, while you are there have a look at the new acoustics, nowadays they come in a variety of sizes, you may find something like a grand auditorium or grand acoustic will suffice.
