best ask your accountant about the ltd company,my understanding is that if they c you as one business then u will have to pay vat on the whole lot.i think u can split the business if different ie commercial business and a domestic business.but a grey area.
I went vat severasl yrs ago and pay a flat rate of 12% .so loose out on the domestic and gain on the commercial. I did it mainly as I have a lot of commercial.
I would be tempted to stay as u r ,unless u want to grow your business i think u need at least 3 vans if u are going to expand.3 vans will give u 1 income (hopefully)
but employing is not easy .its a different game to dong it on your tod.
good luck