I was in your same boat. I started out with a back pack blower, line trimmer, a push mower and a 48 inch mower all packed into the back of my truck. I bought shindaiwa, e-mark and snapper equipment. The dealer was able to let me finance the equipmet. This has helped me over time. With new equipment you have less of a chance of a brake down. I hope this helps.
Also look in the search area, this is were I got all my advice. There is some great information out there for a lot of great people.
What I always tell members just starting out is to get the biggest and best mower you can afford that you can use on the lawns you are targeting. Also get the best power tools you can get, but get commercial equipment. Here is a link on Starting a Business with 25 threads with hundreds of posts. This may help you a lot. Also go to my Lawnsite Search Page where I have 72 search topics to find all sorts of threads and posts on about anything you want. Here is the search for Starting a Biz. http://www.lawnsite.com/search.php?...ctname=yes&action=dosearch&getdaily=&pagenum=
To go to my search page, click on the middle link below. If you find it useful, book mark it in your favorites.
If you want upgrades look at echo's srm2601 or pro-attachment series for trimmers, and pb230 or pb210e blowers
on the exmark, if you have the money, buy a hydro.
when you do buy a trailer , (don't make the common mistake) get one a little oversized. (6'x 12')