300mg is plenty. Even 250mg is good. If your diet is in place and you know how to work hard in the gym, you will make some great gains on 250-300mg. I would split it up, into 2 wkly shots. If you are prone to acne, you are more likely to get acne on gear, so make sure to keep your skin clean. If you hunt around, here on the QA (using the search function), you can find lots of preventative care for acne. The best way to deal with is, is not to let it get bad in the first place. Its an infection of the skin and will spread. By splitting your shots up, half monday and half thursday, you will be able to keep hormones more stable. Stability is key for keeping your skin clear, if you are prone. 

For HCG, a small dose taken a couple times a wk, will keep the testes producing. 250iu 2x wk through the cycle, is the way I would go. Just remember that this is going to create small spikes in test and can also cause acne. For your AI, use 12.5mg arom through the cycle. If you find that you experience high estrogen, you can up it to 25mg ED, but I don't think you will need that much on your test dose. If you are too dry at 12,5mg ED, back down to EOD. When you come off, use your clomid for PCT. 2 wks after last shot, 100mg ED for 1 wk, then 50mg for 2 more wks