Interesting to hear that there seems to be issues regarding RSK. There is no way to completely protect yourself from companies that have financial issues but there are suggestions I would pass on when looking for a replacement.
1. When you get suggestions for alternatives from other people posting, look at their site and see if it is something that looks professional and relates to what you are doing. Other questions to ask them include, how long have you been using the solution? How much additional sales has it generated for you? What is your experience with their telephone support, etc. You can weed out the prentenders with this alone.
2. Contact possible alternative vendors and discuss your goals. Request sites that are similar to what you are doing? If you are doing DTG it is pointless to look at embroidery sites. I would determine what their support hours are and determine if they match your business hours to some degree. I would ask if this is their main business or a just a part of what they do. When I do business with a company that is critical to my success I want to make sure thier focus is on the solution not a side project they are working on.
3. If this is truly a business to you and not a hobby cost of a replacement solution means zero. The only thing that matters is how much can you make using a solution? If a system is "free" and it generates little or no sales is it really "free". I would rather pay $1,000 a month for a solution that generates $5,000 a month in revenue then pay nothing for something that generates little revenue. Also keep in mind all the time spent trying to maintain a system and calling support because of issues is a cost.
We use Deconetwork - incredibly flexible, very stable, and we make money off from it every month.
Over the past three years we have installed and used every viable system on the market including OSS, RSK, Pikiware (now Deconetwork), Inksoft and now Deconetwork. The key to us was having mature, stable, proven solution that allowed us to keep our web site look and feel yet allow for on-line design plus offer affiliate stores. The main players these days seem to be Inksoft and Deconetwork. Both good tools, proven technology and good support. The difference for us was the flexibility. In our signature you can link to our site. As you can see it has the appareance of a regular website. For comparison here is a company that is a competitior to some degree www.animalpaintball.com
. As you can see the Animal site looks like all the other template on-line design sites. We feel being able to have a unique web site appearence gives us an advantage.
Best of luck -