The LM741 is not a great option for your requirements. It would require a dual supply with a minimum voltage of +/- 4.5 Volts (or an isolated 9 Volt supply and a virtual ground using a decoupled voltage divider) , has a fairly low input impedance compared to modern op-amps, and far-from-ideal characteristics including offset drift and poor operation close to supply rail voltages.
Consider instead any of the hundreds or thousands of op-amps designed for single-supply low voltage operation with rail-to-rail I/O (RRIO). A parametric search on one of the major manufacturer sites, such as Texas Instruments, will provide many options.
The summing amplifier design should work perfectly for your purposes if the voltage ranges, desired frequency / bandwidth, and supply requirements are kept in mind.
EDIT: Possible alternative op-amp for stated purpose:
If SMD components are acceptable, the Texas Instruments OPA341 and its dual-channel counterpart, OPA2341 are my go-to choices for applications like this.
These op-amps are specified for single supply operation from 2.7 to 5.5 Volts, and outputs can be driven to within 5 mV of each supply rail for a 100 kOhm load - 200 mV each way if load is low impedance, ~2 kOhm.
Texas Instruments offers free samples of both parts on their web site. These are available only in various small SMD packages, however, not in DIP.
For through-hole DIP, my parts shelves contain the Analog Devices AD8044 quad op-amp, which is specified for 3 to 12 Volt single supply, with a whopping 150 MHz GBW. This op-amp can be driven to within 200 mV of each supply rail, and is designed for loads as low as 150 Ohms. Single (AD8041) and dual (AD8042) versions also exist.
Analog Devices offers free samples for these parts on their web site, but like many Analog Devices components, they are a bit expensive if going into production.
For a more specific recommendation, the following parameters would need to be known at a minimum:
- Signal voltage
- Signal frequency / bandwidth
- Vcc of the circuit
- Whether SMD is acceptable or through-hole DIP parts are required
- Impedance of source
- Impedance of load
- How many op-amp channels are desired per device