You are on the best path (I7, 16 gig ram, 1 TB hard drive. Not sure yet about win 10 but we seem to be going there anyway (computers in general) The "bit better" might be things such as SSD (basically a hard drive that does not move) but they do add some expense (getting less expensive as time goes on). Many of the folks I know have gone to SSD for the initial drive (where operating system resides) for the quicker boot-up. Some have gone to SSD for "storage" but many still use the basic hard drives. 1 TB hard drive is good but depending on how many records, etc. you keep, perhaps 2 or even 3 TB (they can be had for not all that much more at times) might serve you well too. If you want to keep the system for a while and want the continued quickness consider possibly going up to 24 or 32 gig ram.
Many programs can use the ram for normal operation and do not need to access the "hard drive" as often - so more ram the better and the easier access for your system. By the way, will you be using a 64 bit or 32 bit system --- 64 will operate a bit faster (you may not notice but the computer will).
Pricing seems about right ---- make sure you also have a good graphics card (multiple monitor availability) and that the card will "stand-up" to heavy use --- some systems offered have good spec's all around but fall short with the graphics. Many are integrated (means a built-in part of the mother board) which uses YOUR ram not there own). This basically means your 16 gig ram might only have 8 or 12 gigs available for your processing while the balance is used for graphic, etc. Another reason for higher ram needed to perform best, in some systems.
As processors change (a lot sometimes) go to the Intel site and review the specs. Some I5 might be as good as an I7 and son on. Also CNET.com has good tutorials on spec'ing computers. I use them as "I know enough to make problems for myself" but do not use that knowledge enough to always remember what-is-what; so I relearn as needed. If you can understand and do taxes, computers are "different" but not nearly as exasperating as government regulations (close maybe - your call).
Have a good Thanksgiving and even better holidays to come!