ESC and Motor Choice

[LostCrawler]

I am in the process of building a buggy/KOH and need some help on deciding the esc and motor. I have some solid rod and brake line on it, so it has alittle wait to it. I currently have 2 scx10 and I am running FXR and a hw 30 and hw35 on 3s with 17 and 20 pinions. So I know what speed they are but I am looking for something different, I want more power, but at the same time I am scared to try the unknown. I am considering brushless. I have been searching for days on here and hear conflicting stories on brushless and I know I need to get sensored but not sure what KV to get to get more speed and torque then a 35 on 3s. I have bugged Mr. Holmes lately and so I decided to get on here the 1.9 section since I will be using them with SCX tranny and axles. My main choices are sticking with brushed and using Holmes BRXl or get MMP and having the option of brushed and brushless. Then what engine 13t CM or try 25t TM or go brushless, I need your input on what size to get. I know I can go to 4s with these esc too, but will 30t and 35t be ok on 4s if I gear up and stay at 17 or 20t on 4s? I appreciate any input on these ESC's and would like to know how your truck is set up like pinion size and lipo size. I still want the good slow and torque crawlability but want some crazy speed. I don't want to mess with the whole 2 speed tranny either. Sorry to be lengthy, my lhs guy doesn't know much or isn't really up to date on the crawling thing and I don't know any body else to ask in my area.
Thanks