Do you need plans? The pictures shows a lot and I'm sure you could do a few things better.
I'd look at buying linear rails/feedscrew out of china(Aliexpress). You can often get scrap steel beam off cuts at tips shops. A 150-200mm PFC(with the back of it up would be great to span the tank and bolt the pillow block onto. Or an I beam or chunk box section offcut.
Copy/get ideas for vices and other bits from saws at your local club.
Look around for something to covert to make the tank.If it was me I'd put the roughly $90aud towards saw parts not the plans.
That is just if I was building one. You just need to get it all prefectly parallel. If you were spanning the tank on round rails I'd probably go 30mm solid shaft. Just need to finds them with cheap postage as they are not light. Maybe you could get stainless shaft locally to match linear bearings or make you own bearings to suit the shaft.
CheersMB