When downgrading your ADSL line u need to think of the following:\
-How many ppl are using the line(2 or more will strain a 384 line)
-Will you be using multiple applications needing internet access(eg downloading youtube vid and play COD4 would result in major lag on a 384 line)
As for bandwidth look at how much you used previous and whether it was local or international bandwidth. Then check on whether u need unshaped or shaped b/w(eg int gaming requires unshaped b/w to play with a respectable ping)
A cool option i found was IS semishaped
the b/w is shaped during office hours and unshaped the rest of the time,
For local b/w i'd also look at IS Fix accounts a 30 gig local + 2 gigs international is R138 (if u don't disconnect the account you can get up to 30 gig int on it :>)
I'd get the bandwidth from
Vanilla (
http://vanilla.co.za/dsl_faq.php) They have some really cool payment and b/w option. U can get IS SAIX or MTN b/w from them. The supports pretty sweet 2.
or
web africa (
http://www.webafrica.co.za/adsl/)