Looks like you can pay per hour, per mile or per load
It would probably be better for you to locate a Man in West Sussex to get your item to you - why not find a Man and ask him?
I recently used Anyvan who act as a host site and interested parties bid for your business. I paid £58 for one item from Nottingham to Brighton. I wasn't in a hurry so they waited until they were coming this way.
have a look at a site called Uship, i brought a wardrobe from just outside bristol and had it delivered here to north devon by a courier, lots of companys and independant guys will offer you bids to transport it for you, id take a look at least. worked out great for me
You'll pay through the nose if you want the same day delivery option, need an accomplice to load and unload the sofa or unwilling to have the van to yourself.
Some drivers object to travelling longer distances although your sofa will probably travel less than 100 miles which should be a two hour drive. So should be 1/2 a days work at most (there and back)
Maybe the cheapest solution is to hire a van yourself for the day hoping there is someone at either end to load/unload.