DBspaces and detached indexes

Well I've sorted through oncheck -pt and got the number of pages out, and fed them into Excel - what a useful program that is! Anyway, I have wound up wondering if for the few large dynamic tables that will again have their own Dbspaces (the data will be on a round-robin basis) if each index should have it's own dbspace, or if it won't make a lot of different to put a couple in a dbspace togeather. The OS will be Solaris 8, the IDS 7.3x, and the table with the most rows in question has nearly 23,000,000 rows currently, plus 4 indexes. Three are on a single column, the 4th is on 3 columns. There is lots of space to go at on the new machine, not to mention masses of RAM, but there is a constraint that I have to create a schema that can also be implemented (once the mirrors have been broken) on the old machine so we can use archive tapes to get a copy of the live DB on it. However I plan to do my disk layout first and then check to see if it can be created on the old machine and adjust if necessary - hopefully it won't be, except that I will have to use maximum size slices to 2 GB (remember we will still be using v7, not the later v9 where this is no longer the case) and offsets as the old machine doesn't have Veritas so is limited as to how many slices can be created on each disk. Hopefully the gurus here will have something useful to say....