Really need some advice as to the best type of solar pump to use

www.solarinovationstore.com has solar powered pumps with battery backup.

Here is a site that lists the top three:

http://www.bestpondpumps.net/3-best-solar-powered-pond-fountain-water-pumps/

Water pumps are rated in how much water (gallons per hour) can be pumped, and how high (max head) that water can be pumped to. Here is an article that details how to figure what size of pump you need. https://www.pondmarket.com/pondinfo/how-to-choose-pond-pumpswaterfall-pumps-and-pond-filter-pumps/

Solar powered pumps that deliver 250 gph require one or more solar panels. For night use these collectors must be hooked to batteries. If you have fish in your pond it is important to keep water moving 24/7 and you might be better off with a standard electric powered pump. Here is a provider of solar pumps: http://www.siliconsolar.com/solar-waterfall-fountain-pump-kits-diy.html I don't know if they are the best, but you can do a search for "solar water pumps review" to find articles with opinions.