New CRM/Sales/Training Database

manager imports lists of data to call
manager assigns leads to Telesales
Telesales calls and makes appointment
Telesales can see Salesmens diaries
Salesman attends appointment and makes sale
Admin sends sale referral to Grant authority
Admin liaises with Grant authority, when Grant has been offered, sends pro-forma invoice
Admin collects payment, links payment to pro-forma, marks pro-forma as paid, sends Tax invoice
Admin organises Training
Training on premises - no venue required - or may need venue - Training has Venue field
Admin sees Trainers diaries - assigns Trainer
Trainer delivers training, collects attendance information, quality feedback, up sell sales information expenses amounts

5 roles - Manager, Telesales, Salesman, Admin, Trainer- some users do more than one role

Leads - company, person, name address, phone, email, various other fields, etc
Statuses: imported, telesales, salesman, etc

Multiple Notes against each lead - user/date/time
Attach multiple Documents to Lead - user/date/time
Multiple Diary entries against each lead - user/date/time who made the entry, user/date/time/place/description who will do the activity

Diary entries - user updates them to held/not held, duration, expenses amounts

One training activity can be linked to multiple leads - when it is a classroom type training

most users only see leads and related records they are assigned to, manager users see all

Filters on all screens/reports on various fields, one/some/all values
Reports of Leads, Activities (calls, meetings, training), Diaries - what do I have to do?, Audit reports - who did what in the database, Pro-forma Invoices, Payments, Tax Invoices.

For reports filter for Telesale(s) and/or one/some/all Salesman(men)

10 users

First version within two weeks of acceptance,
several rounds of user testing, adjustments after install

What language/database would you use?
Have you developed anything similar?
Where are you based?