I have had a junker energon Scorponok/Mega Zarak - the green and yellow one - for ages. It was missing all its accessories, including the visor and feet. Last week I snapped and decided to try make something better of it.
I used the feet from a junker titanium Fallen. I think they look good but it didn't work as well as I hoped. I had hoped for them to be able to flip over for alt mode but no go. I don't think they're noticeable in alt mode though.
I used my soldering gun to melt out a space for a titan master socket and repainted a Fangry titan master. It looks a little bit small but bulking it out would mess up Zarak.
I ain't going anywhere near jet mode.