I agree with drawing the water down making it easier to catch fish. If you take it down to 1/4 tank, you should be able to net your fish and the shrimp with a reasonably sized net.
Try to save as much of the original water as possible. This will make the change easier on the fish. They're going to go through enough without having to cope with new water.
Have you tried patching the leaking tank? Do you know where the leak is? While you're waiting on the replacement, get some sealant made for aquariums. Don't use the stuff from the LHS
because it contains arsenic. If your leak is on a corner, you could lower the water level, dry the area out and apply a coat of sealant, let it cure overnight and refill to test. If your leak is somewhere along the bottom of the tank, you would most likely need to take the tank down to fix it. I don't want to question your wisdom but are you absolutely sure the leak is coming from the tank and not some hose or fixture? The reason I say this is that I once had what I thought was a leak but it was really coming from a light fixture that was over an open area of surface water. Bubbles popping on the water surface splashed up onto the fixture enough to cause a drip off the edge of the fixture. It wasn't enough to cause a big wet spot but it was more than evaporation. A similar problem could exist with an air hose over the edge of the tank. Just checking. In any case, if you have room to store it, your old (fixed) tank could come in handy for times when you need to pull water from your show tank.
Your post refers to your new tank as glass acrylic? Which is it? My own note about acrylic. It scratches easily. I considered acrylic for the weight savings but discounted it because of the maintenance considerations. It's also more expensive than glass.