I agree with most of what has been suggested. I'm not sure how cheaply 5 x 4 enlargers are found here though, but I'd suggest starting with an enlarger such as the LPL C7700 MX which will take you up to 6 x 7 cm and into colour. I started with a second-hand 35mm enlarger and various other bits I got for about $150 AUD. Personally I've never tried stainless reels, so I'd recommend starting with plastic. And that clear plastic tubing you buy by the metre at hardwarde shops works fine for washing.