I don't think too many companies will allow you to run persistent processes on a shared hosting plan and I wouldn't want to be hosting with one that did, it could prove to be a nightmare for others on the shared box.
Your best, albeit relatively expensive, option would be a dedicated server. Unfortunately DreamHost does not currently offer their own dedicated servers. I am not sure when in the future DreamHost will begin to offer their own dedicated servers, but for now they have done a deal with hosting.com (see link below).
Save [color=#CC0000][b]$50[/b][/color] on DreamHost hosting using promo code [color=#CC0000][b]SAVEMONEY[/b][/color] ( Click for promo code details )