The mini DisplayPort to DVI adapter will work great, so your 27" monitor is in.
The VGA monitor is problematic. HDMI and DVI share almost identical digital video signals, so any HDMI to DVI adapter (like the included one) has few (if any) conversion chips in it and the output DVI port will be DVI-D (digital only). DVI to VGA adapters also don't have conversion chips because they use DVI-I or DVI-A ports (A is analog only and I id both analog and digital): they take the DVI analog signal and move it straight to the VGA port. Unfortunately, that means that you cannot go from HDMI to VGA via DVI. You'll need a more expensive converter like this or this.
tl;dr: You can't go from HDMI to VGA without a converter; see the links for examples. For the dual-link DVI you need, the adapter you mentioned that will use the Thunderbolt port will work excellently.
It should be fine. Apple themselves offer to sell you a 27" display along with the laptop so it clearly is capable of driving that many pixels.
I myself use a 15" 2012 MBP Retina with one of those mini DisplayPort to Dual-Link DVI adapters (hooked up to a Hazro 27" monitor, so cheap no-frills much like you're considering) and its been pretty good. This is in addition to also driving a cinema display of the same size, so I have two external monitors.
I read a lot of reviews around the Internet before buying it, and there's a few horror stories (most of them say make sure you get one with firmware 1.03, but there's no way to tell what firmware you have, till you plug it in! - fortunately mine was 1.03 from the off).
The only issue I have with mine is occasionally (maybe once or twice a day) the Hazro monitor goes blank for a second, then comes back on. I have no idea whats causing this, the MBP doesn't even notice (doesn't try to rearrange windows or anything) and its infrequent enough that I just live with it. It may be a slight incompatibility between some of the equipment.
I do suffer from some occasional oddities if I unplug the external monitors while the MBP is asleep, then wake it up (the internal screen won't come on, I think its the graphics card drivers crashing at the unexpected situation) but I don't believe thats related to the Dual-Link DVI.
Best Answer
The Dual Link DVI adaptor is for connecting screens ~30" – not for connect multiple screens.
You would need to connect one via the Thunderbolt port and one via the HDMI port.