In my experience, none of the available "Wed Accellerators" do a damned thing of value. If dialup is your only option, about your only option is to look at multi-link; your ISP configures your account, at extra charge, of course, to allow 2 or more modems, each operating on its own phone line, which of course costs extra for each phone line. There are a couple decent outboard twin modems available; I've had success with 3Com's
3C-888 "OfficeConnect Dual 56K Lan Modem, and Windows itself has provision for using more than one modem ... provided you have more than one modem and more than one phoneline.