Couple of thoughts on this subject:
First, the rocker arms you are looking at on ebay I would not buy, and here is why based on my judgement: First, the material they are made of is inferior and not tested, you will get low life from them. Second, the bearings, when they go could really damage your motor. Third, setting them up - You will have many problems getting them properly aligned, side load etc.... I would not be worth it in the long run.
Ma' Mopar factorys are decent - not the best, but reliable. If you are on a true budget, these still produce decent power and are reliable.
Next - The ductiles - Excellent for the price - relaible, reusable and SOLID
Aluminums - Harland - Comp, etc are great, but the draw backs I see is you need to check in on them, they have a life span and they too fail, but are more accurate on there engineering, material, and reliablity. (Yes, this will open a thread or two on debates)
T&D / RAS: The best - but plan on spending $$$$$$$$$$ -, and your choise of aluminum or steel, I am a steel guy- (Comp/RAS)
And the Jesel - MANY $$$$$$$$$
So when I look at this my debates are on the build type. I personally prefer the bronze shimmed steel with hardend shafts. I send mine to RAS to have them inspected, oil holes cleaned and all checked before use. I have had a set of 440 sources and did not like them. In my judgement they are better than the ones you are looking at on ebay, but they are sloppy, take time to set up and will probably fail in the long run. (but have not yet) I also have the ductiles on mechanical cam - They are great. I also have bought RAS - The best in my book for all around.
Sorry for the rant, but I have spent (wasted) too much money on this and just want to pass my "Market Research" on to the next. I am not a pro motor builder, NHRA specialist, etc, just a Mopar fan with expensive and not always favorable experience.
- Hope this helps
