I would not call what you are describing as going ampless. Ampless usually means you are relying on IEMs or on monitors that are provided by the audio tech.
What you are describing is probably more of an Full Range, Flat Response approach (FRFR). The reason I say this is you indicate intent to plug straight into monitors, rather than having your signal routed to front of house (FOH).
With an ampless approach, your signal typically goes to the front FOH mixer. The signal is blended with other sound sources and sent back to either your IEMs or fold back monitor. The interface you use can range from a regular DI to some sort of "fly rig" that you spec out.
There is also sort of a hybrid approach where you use something like a Rolls PM351. The PM351 serves as a mini mixer, a DI for your bass, and a mic splitter for your vocal mic. Your bass and vocal mic are plugged into the PM351. A monitor send from FOH is also plugged into the PM351. This allows you to directly control the level of your bass, vocals, and the monitor mix. The downside is the PM351 does not give you any tone controls or protective limiting.
The signals from your bass and vocal mic also pass unprocessed through the PM351, and are routed to the FOH mixer.
If I consistently worked with a skilled audio tech, I would probably not use a PM351. They tend to be most advantageous when you don't have a skilled audio tech, or the audio system is not capable of giving you a custom mix.
Modern digital consoles often have the ability for you to control a custom mix on a cell phone or tablet.
When the bassist is running through an amp, I normally prefer for them to send me a Pre EQ signal. This allows the bass player to dial in his/her stage sound without impacting the signal I receive at FOH.
However, in the event that you are using IEMs or a foldback monitor, instead of an amp, I think it's a good idea for you to have some tone controls at your finger tips. Way easier for you to dial in the sound you want, than to talk me through the necessary adjustments. However, you need to be aware that any adjustments you make will have an impact on all of the mixes. So try to get your tone dialed in early and then try to lock it down, rather than fiddling with it during the show. Also you may need to negotiate with the audio tech if you use really aggressive EQ.
In my experience, it's important to choose a cab/monitor that works well with bass. This can vary somewhat with the type of sound you prefer. I have used several decent foldback monitors that worked really well with vocals, but they did not work well with bass. For context I actually like playing bass through a true FRFR system.
Also, keep in mind that many cabs that are claimed to be FRFR are actually designed for guitar players who use amp modelers. They may not be true FRFR with bass, as they may not carry the low end very well. Or they may work okay with bass as long as you don't need a lot of volume. Many of these so called FRFR cabs have ridiculous specs that are pretty much BS. Before buying, make sure you do enough research to make sure you understand the capabilities of the gear you are considering.
