At $190 for a 45W kit, the HF solar charger is actually quite expensive for the size and poor quality.
I have a 160W (2x80W) solar array on my M/H with a 20A charge controller.
These are the panels that I have:
http://www.ebay.com/itm/80W-Polycrystalline-Solar-Panel-18V-TUV-RV-Motorhome-Boat-Poly-80-Watt-/380565385638?pt=LH_DefaultDomain_0&hash=item589b76f1a6
I have this inexpensive 20A controller:
http://www.ebay.com/itm/10A-20A-30A-12-24-Auto-Distinguish-Switch-Solar-Light-Panel-Charge-Controller-/110947577747?pt=LH_DefaultDomain_0&var=&hash=item19d4fdaf93
Including wire, I have less that $400 in the system. We just got back from 6 days of dry camping and never gave a thought to the batteries. It was in the low 40s at night and we ran the furnace all night. We have all LED lights:
http://www.amazon.com/gp/product/B007BSG760/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1
If you are going to keep your current battery, I would recommend 1, 80W solar panel but still get the 20A controller and 10g wire, in case you want to upgrade. Then it would just be a matter of adding another 80W panel to your existing set-up.
This is the wire that I bought:
http://www.ebay.com/itm/NEW-A-W-I-Tinned-Marine-Wire-10-2-SAE-FOR-Bilge-MACERATOR-Pump-40-FEET-USA-MADE-/310656217382?pt=Boat_Parts_Accessories_Gear&hash=item48548db126&vxp=mtr
The key is your battery. It's important to match your solar with the amount of battery storage that you have. If you are going to keep your current battery, there's no point in going to a larger solar array that 80W, just to have the battery fully charged by noon (on most days).. 1, 80W Panel @ less than $200 would give you nearly double that output of the HF solar panel kit and these are real solar panels, the ones that HF sell are toys in comparison.
If you do decide to upgrade your battery to 2x 6V golf cart batteries:
http://www.thesolarbiz.com/Trojan-T-105-6V-Battery?gclid=CMLIwqf53rYCFUxxQgodFBgAow#.UXWHIcph5js
then you might want to add another 80W panel and have 2 to 3 times the storage of what you have now and the capacity to keep it charged, even on partially Sunny days.
One very important point........ if you decide to upgrade to dual batteries (of any kind), be sure to buy 2,
new matched batteries (same brand/model# and date of manuf). Never try to add a new battery with an older battery.