Workbench 3.5/3.9. Worth upgrade?

[SidVicious]

I'm now using Workbench 3.0. Is it worth it to buy i new ROM and Workbench 3.5 or 3.9. What's the best choise?
I have 50mhz Blizzard card with 68030 CPU,68882 FPU and 32mb EDO RAM and a extern AmiQuest Overdrive HD 4.2gb, everything in my little Amiga 1200.
Will 3.9 and 3.5 go much slower then 3.0? Is it realy needed to use a graphic card? Doez it make a big perforance kick when only using workbench? Right now, i'm mostly using MOD play programs and Deluxe Paint.
And what version of Kickstart is Kickstart ROM v. 39.106? (3.0 or 3.1?)

[SidVicious]

How do i softkick 3.1?
I'll go and buy version 3.9 as soon as possible then. Sounds great! Does it work fine if i run it at 64 colors too? ?_?
Is there any good guide on how to build in a A1200 in a tower case?

[SidVicious]

Where's that shop located? What's the chiping prize for WB3.9 and ROM 3.1.

[SidVicious]

Why does there needs to be a new ROM at all? Would be better if it was possible to flash the ROM like the PC bios or something.