for economy of chemicals you need to use your tank in horizontal mode which also means you must use constant agitation.
So that chemicals do not pool at either end of tank it is best to put tank on roller base (or processor).
If you are considering a processor, then you must also consider if you want to use the lift accessory. If the answer is Yes then your tanks must have cog lids. If you don't want to use the lift then its better to have non cog lids with plug lids. tanks numbers ending in 1 have plug lids. Tank numbers ending in a 3 have cog lids. You can buy spare lids of either type. Tank numbers ending in 1 come with magnets in the base which are for use on a processor without a lift. Spare magnets can be fitted to tank number ending in 3 so that those tanks can be used on processors without a lift. So tanks with a cog lid can be used with or without a lift if they gave a magnet fitted to the base.
Expert drums always have cogs fitted to lids and can only be used on processors with a lift.
If you start without a processor, then you will require a roller base unless you want to do inversion processing(much less economical especially for E6).
For 4x5 film I would recommend a 2551(no cog) or 2553(cog lid) tank which takes two 2509n reels each holding 6 sheets of 4x5 film. It is uneconomical to use the tank with only 1 reel because you still have to use enough chemistry for 12 sheets of film when in horizontal mode.
For 8x10 the 3005 expert drum is probably the best but it is very expensive.
Also it can only be used on a processor with a lift so if you get this drum and want a processor then all your other tanks should also have cog lids.
I don't know about using a print drum for 8x10 film.
The roller base is cheap and means you can start without having to get a processor. And for E6 you really will need the roller base or a processor because the tanks need to be kept horizontal.