noobie here, got an arrow question for ya...
 

So I have a mathews Drenalin and need to get some arrows. 28.5 in. Draw, 70 lbs. Previous owner shot 27's, but seems a litfle short. What brands, length and spine recommendations touch guys got? Thanks!

My recommendation would be gold Tip 7595s. You can usually pick them up on Ebay. Do a search for blemished ones. this is only a cosmetic blemish in the camo pattern and are just fine. You would probably want them cut to 30" is your draw is 28.5"

What weight of broad head with that?

If it were me I would shoot 100 gr heads. But there is nothing stopping you from going to a 125 gr or heavier. A rule of thumb is you loose 1 fps per each 5 grain increase. So going from a 100 to a 125 you will loose around 5 fps but will have increase penetration. The heavier head will also make the shaft behave as a slightly weaker spine which wont hurt your set up one bit.