You didn't list keyboard and mouse (Don't know if that's what you meant by "no peripherals" needed).
Re: your specified configuration, it depends on any requirements you have to balance high performance or high-capacity local
storage. Since you specified a 128GB SSD, I'm assuming
you are relying on networked or "cloud" storage? 128GB is not very much storage these days. It also doesn't provide for any ability to backup your system and project data unless you're using networked (or removable) storage media.
Re: performance considerations...if you don't have a need for blinding speed while images load and/or redraw you can make do with a lower performance CPU and/or slower (usually less expensive) and lower amounts of RAM (although I'd consider your specified 4GB the absolute
minimum). The savings can be invested in a higher capacity drive or multiple drives and the ability to include local backup capability.
You may also consider leveraging your requirements so you can invest more in a keyboard with user-definable macro-keys like Microsoft Sidekick X4 (a new X4 can be sometimes found on sale for as little as $50, (on sale at places like newegg.com
)) or similar. Macros can be very useful on graphics packages. A keyboard with the ability to define and record macros "on the fly" (without having to access any macro-writing software) can also be a plus.
Personally, I like the X4's tactile "feel" and macro software. Others don't. A perk is that it's illuminated so is easy to use in low-light areas...which can be encountered when doing graphics production work.
A "decent" mouse can also set you back about $50. A mouse, especially when doing graphic work, can be a VERY key element of productivity and comfort. Again, my personal preference is to NOT use a mouse with a lot of user-definable buttons. I prefer setting and using keyboard macros, as I find using a mouse with more than 7 "buttons" difficult. However...strictly a matter of user preference. You may also want to use a mouse with selectable DPI...as that can make switching between general graphic work and "fine" graphic work a bit easier.