New computer desk/table for my mother with better ergonomics

[MauveCloud]

My mother has been getting neck pain very quickly when using her computer, to the point that she had me uninstall Everett Kaser games from her machine (which were moderately addictive for her). She's 5'2" and has been using a slanted footrest, which I figure indicates that her chair and desk are a few inches too high for her.

I plan to take her to a nearby Staples so she can try some rolling office chairs (she has been using a Virco 8925 stacking chair, which my father and I like better than rolling office chairs, but last night when we asked her about her desk situation, she mentioned being frustrated about the difficult of pushing the chair back to get access to more of the keyboard). We might also decide to get a floor mat so it can roll easier.

The desk she has now is 48" wide, 30" deep, and 29" high, with a plastic Kensington keyboard tray added that has a ridge around all the sides, including a bit in front that makes it uncomfortable to use a mouse (she's been using a Cherry G80-11900HRMUS/05 keyboard that has a built-in Synaptics touchpad in the lower right), plus the width inside the ridges is only 24". She keeps papers on top of the desk, so I don't think she'd be happy with a significantly smaller desk (other than height-wise), and there isn't really room for a bigger one.

As far as budget, under US$500 would be nice, but willing to consider up to $1000.

Here's what I'm currently considering:
30" x 48" Rectangular Adjustable Activity Table in Maple Edge Banding: Black, Leg Color: Black, Leg Style: Standard Leg Ball Glides

Alera Valencia Series Underdesk Keyboard/Mouse Shelf, 28 by 12, Mahogany

Ergotron LX Desk Mount LCD Arm, Tall Pole

KB & Mouse: http://pcpartpicker.com/p/1946U
(She doesn't care about mechanical keyboards or laser mice, so I don't plan to spend much on these, but the spare keyboards and mice I have are rather worn)

Her current monitor: Acer S231HLbid
Her current speakers: Logitech Z130
Her current case: Cooler Master Elite 311

Are there any problems I might have missed with the components I've chosen, or cheaper/better alternatives I could consider?

 

[getochkn]

flip desk upside down, take jig or circular saw, cut off an inch around the bottom. fixed. lol.

That's why I build all my own desks. I'm not craftsman but anymeans, but some straight cuts on some particle board or mdf and some screws and that's all a desk is, and mine are usually 1000 times more stable than some staples wobbly crap that cost like $500.

 

[MauveCloud]

I mentioned that idea to my father, and he pointed out that we don't have the skills or the tools for that. You say you're not a craftsman, but if you've been building your own desks for a while, that makes you more of a craftsman than us. Another potential problem is that I don't remember whether the screws that attach the long "feet" to the side panels are glued in - we've had the desk for more than 20 years, and it might have been somebody else who assembled it. I'd rather pay for a new desk/table than risk ruining the one we have now (after which, we'd be forced to buy a new one anyway).