IMO you would be better off with a Tajima or Barudan, Tajima machines are distributed by Hirsch Intl and they are located in NY so your tech services will be very available.
Both of the above mentioned machines have a large sewing field that fits your needs and are a stand alone machine that do not require you to attach your computer to the embroidery machine. Melco machines require an external computer to be loaded with the operating software in order for the machine to operate so if your computer has a problem ( plethora of possible problems) your embroidery machine will not operate. On the other hand with a machine that has its own built in computer you can store designs on flash media or floppy and when required load and run, all you need is power, a small 3500 watt generator will run any machine you may need. Just run it through a back up power supply to condition the power.
I cannot give you hands on information on the Ricoma but have not heard a lot of good about the Chinese built embroidery machines and that parts, electronics are hard to come by.
I would also like to add that I have done some guidon work and it is not easy, you need to do two items if it is lettering or one side is backwards and sewn in bobbin thread and designs need to be done with manual wound bobbins to match the top thread, they are very labor intensive as you need to change bobbins with every color change. They can look fabulous when done right.
Check out the machines for sale, there is an almost new TMFX 1501 IIC for sale with under 20,000,000 stitches for 13K that would fill your needs other than software. This is a workhorse, ours has over 95 million stitches with no breakdowns just routine maintenance. That machine for sale has less than 450 hours of run time and is 4 years old, this is less than 120 hours a year.
As always best wishes to all and best of blessings.