Most SS backplates are five to six pounds negative. Some, like FredT, make heavier ones. DSS makes weight plates to bolt onto the SS, that can make it up to 13 lbs negative.
I'm not familiar with the Dive Rite SS plates. The HOG plates we have have nice finish and standard holes and slots. The big differences between plates are 1) finish and deburring; 2) whether they have camband slots or not, and if so, how they are spaced, and 3) whether the plate has holes along the rim or not, and if so, how many, and where are they placed.
I have no experience with Oxycheq wings. They have a loyal following. Their customer service sucks.
If I were going to counsel someone into putting together a rig . . . if you can afford something in the $500 range, buy a DSS setup. The goods are good quality, made in the USA, and customer service rocks. If you are trying to minimize costs, look into the HOG setups. We have them for our students, and the quality seems to be quite acceptable, and the price point is good.