Caleb,

It looks like that pump is a fresh water transfer pump and most likely does not have the corrosive resistant internal parts needed to use with SH. Viton or Santropene are best for this use. Even EPDM is OK but it will not last long. Also, the pump has screew in fittings which will make for a royal pain in the butt when it's time to change a pump. Especially on a job site, which WILL happen. Quick connect, snap fittings are needed. Looks like the price is $110.00. I would call SWS on Monday, when they open and just get a new 5.3 gl/min pump from them. They are just under $200.00 and made for this industry. The extra $80-90 is well worth the aggravation of finding all this out later. The rest of the set up is basic and crude, but I have seen set ups like this work. Just be very cautious about the customers observations of what your equipment looks like when you go to do the job. If they see homemade rigs, tht look like something they can make in their garage, it will raise questions. No matter how good a job you do, will you be able to charge a premium price for your work. Will they remember you for this and recommend you to friends and neighbors, or will they simply get more prices next time they need work done. All these factors play into SWS and our Networks mindset of customer repeat business and professional appearance. I know where you are with respect to money and starting out, but think long term income and not short term expenses. You can make a cheaper rig yourself look better, just add a hose reel and a few PTO tanks from tractor supply, as opposed to using barrels. I personally do not mind tinkering with my rigs but never saw the long term value in continuing to buid my own. I would rather buy one and sell/book out my schedule with that time. Just my opinion. Call me anytime. 

+1 on John's advice. If you are set on getting this set up, or already have it, at least get a 50 gallon tank from a farm supply store, it will make your set up look a little less crude. Also, I assume by your budget you will be doing this in an unmarked personal vehicle, like a truck. Rolling around in a unmarked truck with a 55 gallon drum strapped in will make people wonder, as in "I wonder what nasty chemical that guy has in the back of his truck."

I suppose you could get by without a reel, but I've never heard of anyone doing that. You will want 200' of clear braid hose at the minimum, and fighting with that without a reel will be a nightmare. The reel is the most expensive single component of any system, and a good one is about $300. If you spend much less it will not last a month. If you need to get by without an expensive reel, unhook the hose from the system and roll it up on a cheap plastic reel. You will spend less time connecting and disconnecting the hose than you would fighting with it without a reel, and if you plumb it through a cheap reel it will leak almost immediately. A nice reel with 300" of hose and a tank will go a long way to making you look a little more legit.

A real basic beginner system, ready to go is between $2000 and $3000, and can be used as your back up system when you get a pro-level system. The education is the important investment. Whatever you end up with for a starter system, budget as much of the profit from your first jobs to invest in some classes, see the Academy classes tab on the SoftWash Systems home page.