ARDUINO CONTROLLER SELECTION

Projects General Guidance
1

Dear all,

I need help in selecting proper controller to my application. MY application is solar string monitoring

I have 24 string each going through hall sensor , which gives 0~5v analog output.(there are totally 24 analog channel).

1 voltage transducer which measure 1000v , gives analog output 0~5v .( 1 analog channel)
1 temperature sensor which can measure 70deg and, gives analog output 0~5v .( 1 analog channel)

I need total 18 digital Ios:

8 selector switch,2 serial monitor;2 MODbus communication; 1 dis connector status; 1 for SPD status;
4 LED indicator.

There are totally 26 analog(0~5v output), 20 digital IOS.

Please let me know which controller suit my requirement.
I tried with Arduino UNO using MUX. But i cant manage the Digital IOS. If i am switching to Ardunio Mega. Ic price cost double the arduino UNo, It became high End controller, Which not need to develop this application

Is there any controller available in intermediate to suit my requirement.

2

Maple mini clones are quite cheap and have lots of io but you'd still need to Mux in the analogue sigs